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Maps network ports thru NAT-PMP and refreshes that mapping automatically
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| #!/usr/bin/env bash | |
| # natpmprfr.sh: Maps network ports thru NAT-PMP and refreshes that mapping automatically | |
| # (https://en.wikipedia.org/wiki/NAT_Port_Mapping_Protocol) | |
| # | |
| # Useful for applications with poor or without NAT-PMP implementation | |
| # (http://miniupnp.free.fr/libnatpmp.html) | |
| # | |
| # Can set UFW rules according to mapped/unmapped local ports | |
| # (https://help.ubuntu.com/community/UFW) | |
| # | |
| # Requirements: sudo, natpmpc, ufw (optional) | |
| # Tested on Ubuntu 22.04 LTS | |
| gateway="192.168.1.1" # mat-pmp gateway | |
| local_port="0" # set to 0 to obtain from natpmpc | |
| protocols="tcp" # "tcp" "udp" "tcp udp" | |
| refresh_timeout="40" # seconds | |
| port_file="/tmp/nat-pmp_local_port.txt" # set to "" to disable | |
| set_ufw_rules=true # requires root permissions | |
| map_port() { | |
| if [[ "$protocols" == *"tcp"* ]]; then | |
| natpmc_out=$(sudo -u nobody natpmpc -g "$gateway" -a 0 "$local_port" tcp 60) | |
| local_port=$(echo "$natpmc_out" | grep -Po 'local\sport\s\K\d{0,65535}') | |
| public_port=$(echo "$natpmc_out" | grep -Po 'public\sport\s\K\d{0,65535}') | |
| echo "💻 Local TCP port: $local_port" >/dev/tty | |
| echo "🌐 Public TCP port: $public_port" >/dev/tty | |
| fi | |
| if [[ "$protocols" == *"udp"* ]]; then | |
| natpmc_out=$(sudo -u nobody natpmpc -g "$gateway" -a 0 "$local_port" udp 60) | |
| local_port=$(echo "$natpmc_out" | grep -Po 'local\sport\s\K\d{0,65535}') | |
| public_port=$(echo "$natpmc_out" | grep -Po 'public\sport\s\K\d{0,65535}') | |
| echo "💻 Local UDP port: $local_port" >/dev/tty | |
| echo "🌐 Public UDP port: $public_port" >/dev/tty | |
| fi | |
| if [ -n "$local_port" ]; then | |
| echo "$local_port" | |
| fi | |
| } | |
| ufw_open_port() { | |
| if [ "$set_ufw_rules" = true ]; then | |
| echo "" | |
| echo "🧱 UFW says:" | |
| if [ "$local_port" = "0" ]; then | |
| ufw allow "$1" | |
| else | |
| ufw allow "$local_port" | |
| fi | |
| fi | |
| } | |
| ufw_close_port() { | |
| if [ "$set_ufw_rules" = true ]; then | |
| echo "" | |
| echo "🧱 UFW says:" | |
| if [ "$local_port" = "0" ]; then | |
| ufw delete allow "$1" | |
| else | |
| ufw delete allow "$local_port" | |
| fi | |
| fi | |
| } | |
| write_port_to_file() { | |
| if [ -n "$port_file" ]; then | |
| echo "$1" | sudo -u nobody tee "$port_file" 1>/dev/null | |
| fi | |
| } | |
| unmap_ports() { | |
| echo "" | |
| echo "🌊 Unmapping port(s)..." | |
| if [ -n "$cached_local_port" ]; then | |
| if [[ "$protocols" == *"tcp"* ]]; then | |
| sudo -u nobody natpmpc -g "$gateway" -a "$cached_local_port" "$local_port" tcp 0 1>/dev/null | |
| fi | |
| if [[ "$protocols" == *"udp"* ]]; then | |
| sudo -u nobody natpmpc -g "$gateway" -a "$cached_local_port" "$local_port" udp 0 1>/dev/null | |
| fi | |
| ufw_close_port "$cached_local_port" | |
| fi | |
| } | |
| terminate() { | |
| unmap_ports | |
| rm -f "$port_file" | |
| exit | |
| } | |
| if [ "$set_ufw_rules" = true ]; then | |
| if [ "$EUID" -ne 0 ]; then | |
| echo "Please run as root" | |
| exit | |
| fi | |
| fi | |
| trap terminate SIGINT SIGTERM SIGQUIT SIGABRT | |
| echo "🌎 Getting info..." | |
| if sudo -u nobody natpmpc -g "$gateway"; then | |
| while true; do | |
| echo "" | |
| echo "🔌 Mapping ${protocols^^} port(s)..." | |
| local_port=$(map_port) | |
| if [ -n "$local_port" ]; then | |
| ufw_open_port "$local_port" | |
| write_port_to_file "$local_port" | |
| cached_local_port="$local_port" | |
| else | |
| echo "" | |
| echo "💢 Something went wrong..." | |
| if [ -n "$cached_local_port" ]; then | |
| unmap_ports | |
| cached_local_port="" | |
| rm -f "$port_file" | |
| fi | |
| fi | |
| echo "" | |
| echo "🔄 Refreshing ($(date))..." | |
| sleep "$refresh_timeout" | |
| done | |
| else | |
| exit | |
| fi |
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